2. Too Many Other Racing Goals
To run to your potential in the marathon, the required training is drastically different than any other commonly run racing distance. Training for the marathon requires a very specific 8-12 week training block, which necessitates a singular focus that is often detrimental to your short-term performance at shorter races like the 10K and half marathon.
The mistake of trying to accomplish too many secondary goals while training for a marathon is one of the biggest mistakes I encounter when working with veteran runners. Here’s a typical conversation I’ve had during a first consultation.
Joe Runner: “I want more than anything to qualify for Boston at my next marathon. I am only 8 minutes away from the qualifying time”.
Me: “Great. We have four months to train and looking at the weaknesses in your prior training plan, I can definitely see 8 minutes improvement.”
Joe: “Wow, I am excited! I also want to do two half marathons and shoot for a PR, two local 5K’s to beat my local rival, a 48-hour relay race, and pace my friend through his first marathon.”
Me: “Whoa, wait, what? To drop 8 minutes from your marathon PR, we need to do everything right in this training block. Where are the long runs supposed to go? When can we do any marathon specific workouts if you’re always racing?”
While my example sounds extreme, think of how your last marathon training segments have looked–I bet you’ll see a similarity. Unfortunately, and more often than not, a runner who attempts to accomplish too many secondary goals when training for the marathon realizes poor performances–both at the shorter distance, and the marathon itself, thanks to unspecific training.
Why Marathon Training Is Different
Unlike other events like the 10K, or even the half marathon, training for the marathon necessitates a specific focus on physiological adaptations that aren’t of great importance to shorter races. In the marathon, the primary focus of training is developing your aerobic threshold (the fastest pace you can run while staying aerobic), increasing muscular endurance (how long you can run without your legs falling apart), and fuel efficiency (how efficient you can be at burning fat instead of carbohydrates while running at goal marathon pace). At no other race distance are these three training adaptations so important. Therefore, to train for the marathon correctly, you need to temporarily neglect the specific training demands of shorter events.
Furthermore, to accomplish many of the aforementioned training adaptations, you need to practice running on tired legs or with low energy levels. This philosophy is often called “accumulated fatigue”. Basically, this means that the fatigue from one workout accumulates and transfers to the next so that you’re always starting a workout or a long run a little tired from your previous training. This type of training helps your body adapt to performing better during the last half of the marathon race. Consequently, it’s very difficult to race well at other distances when training appropriately for the marathon because your legs should, and will, often be in a state of accumulated fatigue. More often than not, strong performances at 5K or 10K races during marathon training can indicate that your marathon training isn’t specific enough.
If you’re training for the marathon, you have to realize that performance at a shorter distances will suffer in the short-term. If you still want to run well at other distances, perhaps a marathon isn’t the best goal for this training segment.